// 这是动画的样式
.fourth-page {
    overflow: hidden;
}
.foot {
    width: 1000px;
    margin: auto;
    margin-top: 300px;
    display: flex;
    justify-content: space-between;
}
.middle .yuan {
    background: url(../images/yuan.png) no-repeat #c3c3c3 28px 15px;
    width: 113px;
    height: 113px;
    vertical-align: middle;
    padding: 20px;
    border-radius: 50%;
    position: relative;
    top: 0;
}

/*这里是圈圈的动画 让圈圈不停的动画*/
.border {
    position: absolute;
    left: -9px;
    top: -9px;
    width: 161px;
    height: 161px;
    border: 5px solid #c3c3c3;
    border-radius: 50%;
    animation: border .8s;
    animation-iteration-count: infinite;
}
@keyframes border {
    0% {
        left: -9px;
        top: -9px;
        width: 161px;
        height: 161px;
        opacity: 1;
    }
    100% {
        left: -19px;
        top: -19px;
        width: 181px;
        height: 181px;
        opacity: .1;
    }
}
.middle {
    width: 100px;
    float: left;
    margin-top: -140px;
    margin-right: 45px;
    box-sizing: border-box;
}
// 滚屏开始
.section {
    background-size: cover;
    background-attachment: fixed !important;
    background-repeat: no-repeat;
    width: 100%;
    z-index: -22;
}
// 这是导航的两个样式
.img-res {
    display: block;
    max-width: 100%;
}
.main-header {
    width: 1000px;
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    margin: 0 auto;
    padding-left: 0;
    transition: width 1s, padding-left 1s, background 1s, top 1s;
    background: transparent;
    z-index: 3;
}
.sm-nav{
    width: 100% !important;
    padding: 8px 0;
    padding-left: 50px !important;
    background: linear-gradient(#3C7DC1, #99ddea);
    top: 0 !important;
    box-shadow: 1px 1px 6px #c3c3c3;
}
.main-header .sm-logo {
    width: 180px;
    height: 46px;
}
.db-btn {
    float: right;
    width: 300px;
    height: 100%;
    margin-top: -40px;
}
.db-btn a.download {
    background: linear-gradient(#F45D68, #E54646);
    padding: 0 8px;
    text-align: center;
    border-radius: 3px;
    width: 50px;
    height: 32px;
    line-height: 32px;
    border: 1px solid #C90000;
    color: #ffffff;
    float: left;
    margin-left: 20px;
}
.db-btn a.download:hover {
    background: #F55331;
}
.db-btn a.index {
    background: linear-gradient(#30C37C, #30C37C);
    padding: 0 8px;
    text-align: center;
    border-radius: 3px;
    width: 50px;
    height: 32px;
    line-height: 32px;
    border: 1px solid #30C37C;
    color: #fff;
    float: left;
}
a.index:hover {
    background: #22B14C;
}
h2 {
    text-align: center;
    padding: 0;
    box-sizing: border-box;
    position: relative;
}
h2 img {
    position: absolute;
    top: 100px;
    left: 0;
    right: 0;
    margin: 0 auto;
}
.db-btn a.top-index {
    background: linear-gradient(#FAFAFA, #F2F2F2);
    padding: 0 8px;
    text-align: center;
    border-radius: 3px;
    width: 65px;
    height: 45px;
    line-height: 45px;
    border: 1px solid #F2F2F2;
    color: #444444;
    float: left;
    margin-top: -19px;
}
.db-btn a.top-download {
    background: linear-gradient(#F45D68, #E54646);
    padding: 0 8px;
    text-align: center;
    border-radius: 3px;
    width: 65px;
    height: 45px;
    line-height: 45px;
    border: 1px solid #C90000;
    color: #ffffff;
    float: left;
    margin-left: 20px;
    margin-top: -19px;
}
a.top-download:hover {
    background: #ED1C24;
}
a.top-index:hover {
    background: #F1F1F1;
}